For visual sense,the nerve impulse is generated by

When a neuron is in a resting state,i.e.,not conducting any impulse,the axonal membrane is:

The mineral necessary for nervous conduction is

At the site of stimulation,the charge of the inner and outer surface of the membrane becomes reversed due to:

Consider the statements as True/False:
$I$. The axoplasm inside the axon contains a high concentration of $K^{+}$ and negatively charged proteins.
$II$. The axoplasm inside the axon contains a low concentration of $Na^{+}$.
$III$. The fluid outside the axon contains a low concentration of $K^{+}$.
$IV$. The fluid outside the axon contains a high concentration of $Mg^{++}$ and negatively charged proteins.
The correct option is:

$A$ nerve impulse is defined as .........